High speed printers with staggered fonts

ABSTRACT

A high speed on-the-fly line printer employs print hammers which span five print positions and which are actuatable in sync with a continuously rotating print drum such that each hammer is adapted to print a character in each of the five print positions which it spans. The print drum has a separate font of type characters for each print position, the fonts associated with any one hammer being staggered about the periphery of the drum such that they scan past the hammer one font at a time (all the types of one font passing the hammer before any type of another font passes the hammer). The hammers are driven by electronic control means which generate hammer firing pulses through comparison of the data to be printed against character codes representing the print drum type characters as they come into alignment with the different print positions. The control means operate to fire each hammer a plurality of times to print a plurality of characters during a single revolution of the print drum. The control means inhibits the generation of hammer firing pulses during passage of alternate type fonts past each hammer, thereby permitting adequate hammer recovery time after each firing and enabling each hammer to print its five characters in less than two complete revolutions of the drum.

United States Patent [1 1 Sweeney Nov. 26, 1974 HIGH SPEED PRINTERS WITH[73] Assigneez. Mohawk Data Sciences Corporation,

East Herkimer, NY.

22 Filed: Apr. 18,1973

21 Appl. No.: 352,162

Related US. Application Data [63] Continuation of Ser. No. 178,371,March 8, 1962,

abandoned.

[52] US. Cl 101/93 C, 197/49, 178/32, 340/172.5, 235/619 [51] Int. ClB4lj 5/00 [58] Field of Search 101/93 C, 99, 110,94;

[56] References Cited UNITED STATES PATENTS 373,508 11/1887 Wiley 178/32X 1,838,584 12/1931 Smith 101/94 1,933,650 11/1933 Bascom 340/3182,658,106 11/1953 Hell 178/30 2,757,605 8/1956 Dumey 101/93 C 2,796,8306/1957 Hilton 101/93 C 2,915,967 12/1959 Gehring et a1. .1 101/93 C2,926,602 3/1960 MacDonald et al7 101/93 C 2,949,846 8/1960 Hoffman eta1. 101/93 C 2,978,977 4/1961 Eckert et a1. 101/93 C 3,024,723 3/1962Wasserman 101/93 C 3,128,693 4/1964 Thiemann 101/93 C 3,158,090 11/1964Wasserman 101/93 C 3,220,343 11/1965 Wasserman 101/93 C Print CommandWilkins et al. 101/93 C Wasserman l0I/93 C Primary ExaminerRobert E.Pulfrey Assistant Examiner-E. H. Eickholt Attorney, Agent, or FirmRobertR. Hubbard; Richard H. Smith [57] ABSTRACT A high speed on-the-fly lineprinter employs print hammers which span five print positions and whichare actuatable in sync with a continuously rotating print drum such thateach hammer is adapted to print a character in each of the five printpositions which it spans. The print drum has a separate font of typecharacters for each print position, the fonts associated with any onehammer being staggered about the periphery of the drum such that theyscan past the hammer one font at a time (all the types of one fontpassing the hammer before any type of another font passes the hammer).The hammers are driven by electronic control means which generate hammerfiring pulses through comparison of the data to be printed againstcharacter codes representing the print drum type characters as they comeinto alignment with the different print positions. The control meansoperate to fire each hammer a plurality of times to print a plurality ofcharacters during a single revolution of the print drum. The controlmeans inhibits the generation of hammer firing pulses during passage ofalternate type fonts past each hammer, thereby permitting adequatehammer recovery time after each firing and enabling each hammer to printits five characters in less than two complete revolutions of the drum.

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1. A printer comprising: a print wheel bearing two fonts of charactertypes on different sectors of the wheel and in different columns of itscircumferential surface; a hammer having a face positioned to strikeagainst said character types and having a width sufficient to span eachcolumn; means for rotating said print wheel so that the fonts pass bythe hammer face one at a time sequentially; means for actuating saidhammer when a selected character type in either of said fonts is instriking position; and means for inhibiting the operation of saidactuating means during the passage of one of said fonts for at leastthose wheel revolutions in which the actuating means is operated toactuate said hammer during the passage of the other of said fonts.
 2. AprintEr comprising: a print wheel bearing two pluralities of charactertypes on different sectors of the wheel and in different columns of itscircumferential surface; a hammer having a face positioned to strikeagainst said character types and having a width sufficient to span eachcolumn; means for rotating said print wheel so that the character typepluralities pass by the hammer face one at a time sequentially; meansfor actuating said hammer when a selected character in either of saidpluralities is in striking position; and means for inhibiting theoperation of said actuating means during the passage of one of saidpluralities for at least those wheel revolutions in which the actuatingmeans is operated to actuate said hammer during the passage of the otherof said pluralities.
 3. In a high speed printer, a type carrier assemblyincluding: a movable type carrier adapted to support a plurality ofprinting type arranged in rows in the direction of movement; a pluralityof printing hammers supported in positions to strike the printing type,each of the printing hammers including a head portion arranged to spanat least two rows of the printing type; circuit means to actuate theprinting hammers in accordance with a predetermined logic; the two rowsspanned by a head portion comprising: a first plurality of printing typepositioned in one row; a second plurality of like printing typepositioned in the other of the two rows; and one printing type in thefirst plurality being displaced relative to the corresponding printingtype in the second plurality by a distance at least equal to the lengthof one of said pluralities of printing type, so that the head portion ofthe associated printing hammer can strike any of the printing type inthe first plurality before striking any of the printing type in thesecond plurality; and inhibit means for preventing said circuit meansfrom actuating said hammers for the duration of hammer recoveryintervals, said hammer recovery intervals for each hammer occurring atleast after it has been actuated during the passage by it of the typeplurality in one of its associated rows and each said recovery intervallasting until the type plurality in the other of its associated rows haspassed it by.
 4. In a high speed printer, a type carrier assemblyincluding: a movable carrier means adapted to support a plurality ofprinting type arranged in rows extending in the direction of movement ofthe carrier means; a plurality of printing hammers supported inpositions to strike the printing type, each of the printing hammersincluding a head portion arranged to span at least two rows of theprinting type; a circuit means to actuate the printing hammers inaccordance with a predetermined logic; the two rows spanned by a headportion comprising: all the printing type in one of the two rows beingarranged sequentially in a linear group with a space after the end ofthe group at least equal to the length of the group; all the printingtype in the other of the two rows being arranged sequentially in alinear group similar to the arrangement in the one of the two rows; andthe two groups of printing type being displaced in the direction ofmovement of the carrier means so that the second-mentioned group ispositioned adjacent the space after the first-mentioned group, so thatthe head portion of the associated printing hammer can strike eachprinting type in the first-mentioned group before striking any printingtype in the second-mentioned group; and inhibit means for preventingsaid circuit means from actuating said hammers for the duration ofhammer recovery intervals, said hammer recovery intervals for eachhammer occurring at least after it has been actuated during the passageby it of the plurality of printing type in one of its associated rowsand each said recovery interval lasting until the plurality of printingtype in the other of its associated rows Has passed it by.
 5. In a highspeed printer, a type carrier assembly including: a movable carriermeans adapted to support a plurality of printing type arranged in rowsextending in the direction of movement of the carrier means; a pluralityof printing hammers supported in positions to strike the printing type,each of the printing hammers including a head portion arranged to spanat least three rows of the printing type; circuit means to actuate theprinting hammers in accordance with a predetermined logic; the threerows spanned by a head portion comprising: all the printing type in eachrespective row being arranged sequentially in a linear group with aspace after each group at least equal to twice the length of the group,the spacing between the types within said groups being equal to thespacing between the first and last types in groups which are adjacent toone another in the direction of movement of said carrier means; and eachgroup being displaced relative to the other groups in the direction ofmovement of the carrier means, so that the head portion of theassociated printing hammer can strike the printing type in only onegroup during any one stroke; and inhibit means for preventing saidcircuit means from actuating said hammers during hammer recoveryintervals, said hammer recovery intervals for each hammer occurring atleast after it has been actuated during the passage by it of the typeplurality in one of its associated rows and said recovery intervallasting until the next adjacent type plurality in another of itsassociated rows in the direction of carrier movement has passed it by.6. A printer for printing data in a row of data positions on a documentcomprising: a hammer positioned adjacent said row and having a strikingface spanning a plurality of adjacent data positions; a type carriermovable past said hammer and positioned with respect to said hammer andsaid document so as to cause printing of a selected character on saiddocument when said hammer is actuated, the type being arranged on saidcarrier in a plurality of fonts which pass said hammer one font at atime sequentially as the carrier moves, the type characters within saidfonts being spaced so as to be presented to said hammer one character ata time; means for moving said carrier; timing means operating insynchronism with the movement of said carrier for generating a series ofoutput code characters identifying the sequence in which the typecharacters of at least two of said fonts are presented to said hammer;actuating means responsive to the identity of said selected characterwith one of said output code characters for actuating said hammer tocause printing of the selected character corresponding to said selectedcode in one of said data positions spanned by said hammer; and means forinhibiting the operation of said actuating means during hammer recoveryintervals, said hammer recovery intervals occurring at least after eachhammer actuation which occurs during the passage by said area of a firstof said fonts and said recovery interval lasting until the nextsequentially presented font has scanned past said area.
 7. The printerset forth in claim 6 wherein the plurality of type fonts on said carrieris at least equal in number to the number of data positions spanned bysaid hammer, and wherein said actuating means includes control means forcausing each character printed in said row of data positions by saidhammer to be printed from a different one of said type fonts.
 8. Aprinter for printing data in a row of data positions on a document,comprising: a hammer positioned adjacent said row and having a strikingface spanning a plurality of adjacent data positions; a moving typecharacter member positioned adjacent said row and having on its surfacea plurality of identical, multi-character type fonts arranged to scanpast the area defined by said spanned data positions, said fonts beingoriented such that the characters thereof pass said area one at a timeand such that all the characters of one font pass said area before anyof the characters of another font pass said area; code means operatingin synchronism with the motion of said member for generating a sequenceof code signals representing the type characters of a font in the orderin which they pass said area, said sequence of signals being repeated aseach font passes said area; means for storing coded input datarepresenting characters to be printed in said spanned data positions;signal comparison means for generating pulses to actuate said hammer;means for controlling said signal comparison means to compare differentsequences of said code signals with different ones of said stored inputdata characters whereby each equal comparison results in actuation ofsaid hammer, pressing said document against said member to print acharacter in one of said data positions; and inhibit means forpreventing said control means from actuating said hammer during recoveryintervals, said recovery intervals occurring at least after each hammeractuation which occurs during the passage of a first font by said areaand said recovery interval lasting until the next sequentially presentedfont has passed said area.
 9. The printer set forth in claim 8 whereinsaid control means presents said different stored input data charactersfor comparison in a predetermined sequence determined by the arrangementof said fonts on said type character member.
 10. The printer set forthin claim 8 wherein said inhibiting time interval commences at thetermination of a series of said code signals and lasts at least as longas a series of said code signals.
 11. A printer for printing data in arow of data positions on a document, comprising: a plurality of printhammers positioned adjacent said document, each said hammer spanning aset of adjacent ones of the data positions; a rotating type drumpositioned on the opposite side of said document from said hammers, saiddrum having on its surface a plurality of identical, multi-charactertype fonts arranged such that each font passes serial-by-characterbehind a different one of said data positions as said drum rotates, thefonts associated with the set of data positions spanned by any one ofsaid hammers being oriented such that all the characters of one fontpass their data position before any characters of another font passtheir respective data position; code means operating in synchronism withthe rotation of the drum for generating a series of code signalsrepresenting the characters of a font in the order in which they movepast said row of data positions, said series of code signals beingrepeated as each new type font passes a set of said data positions;means for storing coded input data representing characters to be printedin said data positions, each said character being stored in said storagemeans at a location corresponding to the data position in which thecharacter is to be printed; signal comparison means for generatingpulses to actuate said hammers; means for controlling said comparisonmeans to perform successive comparison sequences, each said sequenceeffecting the comparison of one series of said code signals with aselected plurality of said input data characters, said plurality ofcharacters being selected from those locations in said storage meanscorresponding to the data positions then being passed by a font on saidtype drum, each equal comparison resulting in actuation of an associatedone of said hammers whereby said document is pressed against said drumto print a character; and means for inhibiting said comparison operationduring hammer recovery intervals, said hammer recovery intervals foreach hammer occurring at least after it has been actuated during passageof a font in one of its associated data positions and said hammerrecovery intervals lasting for at least the period oF time required togenerate one of said comparison sequences.
 12. A printer for printingdata in a row of data positions on a document, comprising: a printhammer positioned adjacent said row and having a striking face spanninga plurality of adjacent ones of the data positions; a continuouslyrotatable type drum positioned adjacent said row and mounted forrotation about an axis parallel thereto, said type drum having on itssurface a plurality of groups of type characters positioned to scan, assaid drum rotates, past the area defined by the data positions spannedby said hammer, a different type group being associated with eachdifferent data position, said different groups being arranged to movepast their respective data positions in series such that all charactersof a group are presented to a data position before any characters ofanother group are presented to any other data position; means foractuating said hammer a plurality of times during one revolution of saiddrum, each said actuation operating to force said document into printingengagement with a different one of said type groups to print a characterin a different one of said data positions; and inhibit means forpreventing said actuating means from actuating said hammer during hammerrecovery intervals, said hammer recovery intervals occurring at leastafter said hammer has been actuated during the passage by said area ofone of said fonts and said hammer recovery interval lasting until thenext sequentially presented font has passed by said area.
 13. A printerfor printing data in a row of data positions on a document, comprising:a print hammer positioned adjacent said row and having a striking facespanning a plurality of adjacent ones of the data positions; acontinuously rotatable type drum positioned adjacent said row andmounted for rotation about an axis parallel thereto, said type drumhaving on its surface a plurality of groups of type characterspositioned to scan, as said drum rotates, past the area defined by thedata positions spanned by said hammer, a different type group beingassociated with each different data position, said different groupsbeing arranged to move past their respective data positions in seriessuch that all characters of a group are presented to a data positionbefore any characters of another group are presented to any other dataposition; means for actuating said hammer a plurality of times duringone revolution of said drum, said actuations operating to force saiddocument into printing engagement in a predetermined print sequence withdifferent ones of said type groups to print characters in different onesof said data positions, the spacing between said different ones of saidtype groups, measured along the circumference of said drum from the lastcharacter of one group to the first character of the next said group insaid print sequence, being at least equal to the distance traversed by apoint on the surface of the drum during a time interval equal to theminimum cycle time of said hammer and hammer actuating means; andinhibit means for preventing the actuating means from actuating saidhammer during hammer recovery intervals, said hammer recovery intervalsoccurring at least after said hammer has been actuated during thepassage by said area of one of said type character groups and saidhammer recovery intervals lasting until the next sequentially presentedtype character group has passed by said area.
 14. The printer set forthin claim 13 wherein the spacing between individual type characterswithin each type group is no greater than that required to prevent thestriking face of said hammer from striking an edge portion of thecharacter adjacent the character being printed.
 15. A printer forprinting data in a row of data positions on a document, comprising: aprint hammer positioned adjacent said row and having a striking facespanning a plurality of adjacent ones of the data positions; a type drumpOsitioned adjacent said row and mounted for rotation about an axisparallel thereto; means for rotating said type drum at a substantiallyconstant velocity to move the surface thereof past said row in adirection perpendicular thereto; said type drum having on its surface aplurality of groups of type characters positioned to scan past the areadefined by the data positions spanned by said hammer, a different typegroup being associated with each different data position, said differentgroups being arranged to move past their respective data positions inseries such that all characters of a group are presented to a dataposition before any characters of another group are presented to anyother data position; means for actuating said hammer to force saiddocument into printing engagement with said type drum to print acharacter in a selected one of said data positions; and control meansincluding character position means for generating code signalsidentifying the characters passing said area and comparing means forcomparing said code signals with data to be printed, said comparingmeans operating to generate output signals to activate said hammeractuating means in response to said comparisons, said character positionmeans operating to present said code signals to said comparing means ina sequence wherein each series of code signals representing a type groupis separated by a recovery interval having a duration at least equal tothe time required to generate an entire series of code signals to permitsaid print hammer and said hammer actuating means to recover to theiroriginal condition in preparation for the next print operation.
 16. Aprinter for printing data in a row of data positions on a document,comprising: a print hammer positioned adjacent said row and having astriking face spanning a plurality of adjacent ones of the datapositions; a type carrier positioned adjacent said row; means for movingsaid type carrier at a substantially constant velocity past said row;said type carrier having on its surface a plurality of groups of typecharacters positioned to scan past the area defined by the datapositions spanned by said hammer, said characters being spaced from oneanother in the direction of movement of said type carrier bysubstantially equal amounts, said characters further being arranged suchthat they move past said area one at a time with each of said spanneddata positions being sequentially presented with all the characters ofat least one of said type groups such that they scan past said area onegroup at a time whereby all the characters of one group move past a dataposition before any characters of another group move past any other dataposition; means for actuating said hammer to force said document andsaid type carrier into printing engagement; character position means forgenerating code signals identifying the type characters passing saidarea; control means responsive to said code signals for operating saidhammer actuating means to print selected characters in said datapositions spanned by said hammer; and inhibit means for preventing saidcontrol means from responding to said code signals during a recoveryinterval following each operation of said hammer actuating means, saidrecovery interval being of sufficient duration to permit said printhammer and said hammer actuating means to recover to their originalcondition in preparation for the next print operation, said recoveryinterval lasting until the next sequentially presented character grouphas passed said area.
 17. In a printer for printing data in a row ofdata positions on a document, the combination comprising: a rotatingprint wheel positioned adjacent said row and bearing a number of fontsof character types arranged on different wheel sectors and in differentcolumns of its circumferential surface, so that the fonts scan past thearea defined by said data positions sequentially; a hammer positionedadjacent sAid row and having a striking face spanning all of the wheelcolumns; control means operating in synchronism with the print wheelrotation for selectively actuating said hammer to strike said documentagainst said character types; and inhibit means for preventing saidcontrol means from actuating said hammer during hammer recoveryintervals, said hammer recovery intervals occurring at least after eachhammer actuation which occurs during the passage by said area of a firstof said fonts and said recovery interval lasting until the nextsequentially presented font has scanned past said area.
 18. In a printeras set forth in claim 17 wherein said number is an odd number.
 19. In aprinter as set forth in claim 18 wherein said recovery intervals occurduring the passage by said area of every other font.